A method for preparing carbon steel anti-corrosion composite coating

Abstract

The present invention relates to the field of chemical composite coatings, and in particular to a method for preparing a carbon steel anti-corrosion composite coating. Specifically comprising the following steps: Step 1: mechanically grinding a low-carbon steel sample; Step 2: degreasing the low-carbon steel sample; Step 3: activating the low-carbon steel sample; Step 4: plating the low-carbon steel sample activated in step 3 in a plating solution; the plating solution is composed of sodium dodecyl sulfonate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, heat-treated HA‑SiO2 and deionized water; Step 5: after plating, rinse the low-carbon steel sample with deionized water, then ultrasonicate in anhydrous ethanol for 10 minutes, and then dry for standby use; Step 6: heat-treat the low-carbon steel sample in a muffle furnace at 400°C for 1 hour. The present application further modifies the common SiO2 to improve its corrosion resistance in an acidic environment, while having good acid resistance and alkali resistance.

Description

Technical Field

[0001] The invention relates to the field of chemical composite coatings, and in particular to a method for preparing a carbon steel anti-corrosion composite coating. Background Art

[0002] Material corrosion refers to the phenomenon that the performance of materials gradually decreases during the interaction with the environment. In the application of metals, especially in industrial fields such as oil, gas, chemicals, mineral processing, mining and seawater desalination, the performance degradation and corrosion of metal materials are particularly critical. The corrosion and wear of metal materials are one of the main factors leading to the damage of steel components.

[0003] Chemical plating is a process that reduces metal ions in the plating solution to metals through a reducing agent without applying an external current. Chemical composite plating is a method of co-depositing particles and metal ions on the metal surface through chemical plating technology to form a composite material layer. It is an advanced branch of surface treatment technology. The chemical composite plating technology doped with nanoparticles has the advantages of simple equipment, convenient operation, low cost and easy adjustment. This technology can not only enhance the corrosion resistance, wear resistance and oxidation resistance of the metal surface, but also give the material a beautiful appearance and other unique functions. However, the corrosion resistance of some nano technologies still needs to be improved. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a method for preparing a carbon steel anti-corrosion composite coating.

[0005] The present invention is achieved through the following technical solution: A method for preparing a carbon steel anti-corrosion composite coating comprises the following steps:

[0006] Step 1: Mechanically grind the low carbon steel sample;

[0007] Step 2: Degreasing the low carbon steel sample;

[0008] Step 3: Activate the low carbon steel sample;

[0009] Step 4: Plating the low-carbon steel sample activated in step 3 in a plating solution;

[0010] The plating solution is composed of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, heat-treated HA-SiO2 and deionized water;

[0011] Step 5: After plating, the low-carbon steel sample was rinsed with deionized water, then ultrasonicated in anhydrous ethanol for 10 min, and then dried for later use;

[0012] Step 6: Heat treat the low carbon steel sample in a muffle furnace at 400 °C for 1 h.

[0013] In the prior art, different nanomaterials are added to the plating solution to change the corrosion resistance, wear resistance and other properties of the coating. The present application further modifies the common SiO2 to improve its corrosion resistance in an acidic environment, while also having good acid and alkali resistance.

[0014] Furthermore, in step 4, the preparation method of the plating solution is: take 0.1 mg of sodium dodecyl sulfate and add it to 1 L of deionized water, then add 0.5 g to 4.0 g of heat-treated HA-SiO2, ultrasonicate for 10 minutes, and then add 20 g of nickel sulfate hexahydrate, 24 g of nickel hypophosphite, 16 g of citric acid, and 6 g of sodium succinate in sequence, and ultrasonicate for 30 minutes to obtain.

[0015] Furthermore, the added amount of the heat-treated HA-SiO2 is 3.0 g.

[0016] Furthermore, the preparation method of the heat-treated HA-SiO2 is: SiO2 powder is dispersed in 0.6wt% HNO3, stirred for 2h, hydroxyapatite is added, stirred at room temperature for 96h, and then dried at 50°C to obtain HA-SiO2; wherein the mass ratio of SiO2 to hydroxyapatite is 2:3, and the obtained HA-SiO2 is treated at 800°C for 3h to obtain heat-treated HA-SiO2.

[0017] Furthermore, the mechanical grinding method in step 1 is: the low-carbon steel sample is polished with SiC sandpaper of different particle sizes until the surface is smooth, and the low-carbon steel sample is cleaned with deionized water each time the sandpaper is replaced.

[0018] Furthermore, the particle sizes are 100#, 400#, 500#, 800#, 1200#, and 1500# respectively.

[0019] Furthermore, the degreasing method in step 2 is: ultrasonically treating the low carbon steel sample in acetone for 20 minutes, then ultrasonically treating the low carbon steel sample in a 40 g / L NaOH aqueous solution for 20 minutes, and then washing with water.

[0020] Furthermore, the plating method in step 4 is: after rinsing the low-carbon steel sample with deionized water, immediately place it in a plating solution preheated to 85-90°C; stir the plating solution and maintain the plating temperature at 85-90°C.

[0021] Furthermore, the plating time is 2 to 3 hours, preferably 2 hours.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] The present invention further modifies common SiO2 to improve its corrosion resistance in acidic environment, and at the same time has good acid resistance and alkali resistance. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The illustrative embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0025] In the Q235B grade low carbon steel of the present invention, carbon C: ≤0.20%, silicon Si: ≤0.35%, manganese Mn: ≤1.4%, sulfur S: ≤0.045%, and phosphorus P: ≤0.045%.

[0026] In the present invention, SO2 is purchased from Sigma-Aldrich, with an average particle size of 190-250 nm; HA is hydroxyapatite powder purchased from Sigma-Aldrich.

[0027] Example 1

[0028] The matrix sample is Q235B grade low carbon steel, with a size of 10×10×3 mm 3 , the specific steps are as follows:

[0029] Step 1: Polish the low-carbon steel samples with SiC sandpaper of 100#, 400#, 500#, 800#, 1200#, and 1500# grain sizes until the surface is smooth. Clean the low-carbon steel samples with deionized water each time the sandpaper is changed;

[0030] Step 2: The mild steel sample was ultrasonicated in acetone for 20 min, then ultrasonicated in 40 g / L NaOH aqueous solution for 20 min, and then washed with water;

[0031] Step 3: Activate the low carbon steel sample by soaking it in 5wt% HCl for 5 min;

[0032] Step 4: After rinsing the low-carbon steel sample activated in step 3 with deionized water, immediately place it in a plating solution preheated to 85°C; stir the plating solution and maintain the temperature at 85°C for 2 hours, and observe bubbles in the plating solution;

[0033] The plating solution consists of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, heat-treated HA-SiO2 and deionized water. The preparation method of the plating solution is as follows: 0.1 mg of sodium dodecyl sulfate is added to 1 L of deionized water, then 0.5 g of heat-treated HA-SiO2 is added, ultrasonic treatment is performed for 10 minutes, then 20 g of nickel sulfate hexahydrate, 24 g of nickel hypophosphite, 16 g of citric acid and 6 g of sodium succinate are added in sequence, and ultrasonic treatment is performed for 30 minutes.

[0034] Step 5: After plating, the low-carbon steel sample was rinsed with deionized water, then ultrasonicated in anhydrous ethanol for 10 min, and then dried for later use;

[0035] Step 6: Heat treat the low carbon steel sample in a muffle furnace at 400 °C for 1 h.

[0036] The preparation method of the heat-treated HA-SiO2 is as follows: SiO2 powder is dispersed in 0.6wt% HNO3, stirred for 2h, hydroxyapatite is added, stirred at room temperature for 96h, and then dried at 50°C to obtain HA-SiO2; wherein the mass ratio of SiO2 to hydroxyapatite is 2:3. The obtained HA-SiO2 is treated at 800°C for 3h to obtain heat-treated HA-SiO2.

[0037] Example 2

[0038] The difference between this embodiment and embodiment 1 is that the composition of the plating solution is different.

[0039] Specifically, the plating solution consists of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, heat-treated HA-SiO2 and deionized water; the preparation method of the plating solution is: take 0.1 mg of sodium dodecyl sulfate and add it to 1L of deionized water, then add 1.0g of heat-treated HA-SiO2, ultrasonicate for 10 minutes, then add 20g of nickel sulfate hexahydrate, 24g of nickel hypophosphite, 16g of citric acid, 6g of sodium succinate in sequence, and ultrasonicate for 30 minutes to obtain.

[0040] Example 3

[0041] The difference between this embodiment and embodiment 1 is that the composition of the plating solution is different.

[0042] Specifically, the plating solution consists of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, heat-treated HA-SiO2 and deionized water; the preparation method of the plating solution is: take 0.1 mg of sodium dodecyl sulfate and add it to 1L of deionized water, then add 1.5g of heat-treated HA-SiO2, ultrasonicate for 10 minutes, then add 20g of nickel sulfate hexahydrate, 24g of nickel hypophosphite, 16g of citric acid, 6g of sodium succinate in sequence, and ultrasonicate for 30 minutes to obtain.

[0043] Example 4

[0044] The difference between this embodiment and embodiment 1 is that the composition of the plating solution is different.

[0045] Specifically, the plating solution consists of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, heat-treated HA-SiO2 and deionized water; the preparation method of the plating solution is: take 0.1 mg of sodium dodecyl sulfate and add it to 1L of deionized water, then add 2.0g of heat-treated HA-SiO2, ultrasonicate for 10 minutes, then add 20g of nickel sulfate hexahydrate, 24g of nickel hypophosphite, 16g of citric acid, 6g of sodium succinate in sequence, and ultrasonicate for 30 minutes to obtain.

[0046] Example 5

[0047] The difference between this embodiment and embodiment 1 is that the composition of the plating solution is different.

[0048] Specifically, the plating solution consists of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, heat-treated HA-SiO2 and deionized water; the preparation method of the plating solution is: take 0.1 mg of sodium dodecyl sulfate and add it to 1L of deionized water, then add 3.0g of heat-treated HA-SiO2, ultrasonicate for 10 minutes, and then add 20g of nickel sulfate hexahydrate, 24g of nickel hypophosphite, 16g of citric acid, 6g of sodium succinate in sequence, and ultrasonicate for 30 minutes to obtain.

[0049] Example 6

[0050] The difference between this embodiment and embodiment 1 is that the composition of the plating solution is different.

[0051] Specifically, the plating solution consists of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, heat-treated HA-SiO2 and deionized water; the preparation method of the plating solution is: take 0.1 mg of sodium dodecyl sulfate and add it to 1L of deionized water, then add 4.0g of heat-treated HA-SiO2, ultrasonicate for 10 minutes, then add 20g of nickel sulfate hexahydrate, 24g of nickel hypophosphite, 16g of citric acid, 6g of sodium succinate in sequence, and ultrasonicate for 30 minutes to obtain.

[0052] Comparative Example 1

[0053] The matrix sample is Q235B grade low carbon steel, with a size of 10×10×3 mm 3 , the specific steps are as follows:

[0054] Step 1: Polish the low-carbon steel samples with SiC sandpaper of 100#, 400#, 500#, 800#, 1200#, and 1500# grain sizes until the surface is smooth. Clean the low-carbon steel samples with deionized water each time the sandpaper is changed;

[0055] Step 2: The mild steel sample was ultrasonicated in acetone for 20 min, then ultrasonicated in 40 g / L NaOH aqueous solution for 20 min, and then washed with water;

[0056] Step 3: Activate the low carbon steel sample by soaking it in 5wt% HCl for 5 min;

[0057] Step 4: After rinsing the low-carbon steel sample activated in step 3 with deionized water, immediately place it in a plating solution preheated to 85°C; stir the plating solution and maintain the temperature at 85°C for 2 hours, and observe bubbles in the plating solution;

[0058] The plating solution consists of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, HA-SiO2 and deionized water. The preparation method of the plating solution is as follows: 0.1 mg of sodium dodecyl sulfate is added to 1 L of deionized water, then 1.0 g of HA-SiO2 is added, ultrasonic treatment is performed for 10 minutes, then 20 g of nickel sulfate hexahydrate, 24 g of nickel hypophosphite, 16 g of citric acid and 6 g of sodium succinate are added in sequence, and ultrasonic treatment is performed for 30 minutes.

[0059] Step 5: After plating, the low-carbon steel sample was rinsed with deionized water, then ultrasonicated in anhydrous ethanol for 10 min, and then dried for later use;

[0060] Step 6: Heat treat the low carbon steel sample in a muffle furnace at 400 °C for 1 h.

[0061] The preparation method of the heat-treated HA-SiO2 is as follows: SiO2 powder is dispersed in 0.6wt% HNO3, stirred for 2h, hydroxyapatite is added, stirred at room temperature for 96h, and then dried at 50°C to obtain HA-SiO2; wherein the mass ratio of SiO2 to hydroxyapatite is 2:3.

[0062] Comparative Example 2

[0063] The difference between this comparative example and comparative example 1 is that the composition of the plating solution is different.

[0064] The plating solution consists of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, HA-SiO2 and deionized water. The preparation method of the plating solution is as follows: 0.1 mg of sodium dodecyl sulfate is added to 1 L of deionized water, then 2.0 g of HA-SiO2 is added, ultrasonic treatment is performed for 10 minutes, then 20 g of nickel sulfate hexahydrate, 24 g of nickel hypophosphite, 16 g of citric acid and 6 g of sodium succinate are added in sequence, and ultrasonic treatment is performed for 30 minutes.

[0065] Comparative Example 3

[0066] The difference between this comparative example and comparative example 1 is that the composition of the plating solution is different.

[0067] The plating solution consists of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, HA-SiO2 and deionized water. The preparation method of the plating solution is as follows: 0.1 mg of sodium dodecyl sulfate is added to 1 L of deionized water, then 3.0 g of HA-SiO2 is added, ultrasonic treatment is performed for 10 minutes, then 20 g of nickel sulfate hexahydrate, 24 g of nickel hypophosphite, 16 g of citric acid and 6 g of sodium succinate are added in sequence, and ultrasonic treatment is performed for 30 minutes.

[0068] Test Example 1

[0069] The samples prepared in each embodiment and comparative example were immersed in 15% HCl and 15% NaOH for 240 hours, respectively, and the mass changes of the samples before and after immersion were compared to reflect the acid and alkali resistance. Each measurement was performed three times, and the average value was taken. The ambient temperature was 25°C. The test results are shown in Table 1.

[0070] Table 1 Acid and alkali resistance test

[0071]

[0072] It can be seen from Table 1 that when heat-treated HA-SiO2 is used in the plating solution, the performance is better than that of HA-SiO2 without heat treatment in the acid resistance test, while the performance of the two in an alkaline environment is not much different.

[0073] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a carbon steel anti-corrosion composite coating, characterized in that: The following steps are involved: Step 1: Mechanically grind the low carbon steel sample; Step 2: Degreasing the low carbon steel sample; Step 3: Activate the low carbon steel sample; Step 4: Plating the low-carbon steel sample activated in step 3 in a plating solution; The plating solution is composed of sodium dodecyl sulfate, nickel sulfate hexahydrate, nickel hypophosphite, citric acid, sodium succinate, heat-treated HA-SiO2 and deionized water; The preparation method of the plating solution is as follows: 0.1 mg of sodium dodecyl sulfate is added to 1 L of deionized water, and then 0.5 g to 4.0 g of heat-treated HA-SiO2 is added, ultrasonic treatment is performed for 10 min, and then 20 g of nickel sulfate hexahydrate, 24 g of nickel hypophosphite, 16 g of citric acid, and 6 g of sodium succinate are added in sequence, and ultrasonic treatment is performed for 30 min to obtain; Step 5: After plating, the low-carbon steel sample was rinsed with deionized water, then ultrasonicated in anhydrous ethanol for 10 min, and then dried for later use; Step 6: Heat treat the low carbon steel sample in a muffle furnace at 400 °C for 1 h; The preparation method of the heat-treated HA-SiO2 is as follows: SiO2 powder is dispersed in 0.6wt% HNO3, stirred for 2h, hydroxyapatite is added, stirred at room temperature for 96h, and then dried at 50°C to obtain HA-SiO2; wherein the mass ratio of SiO2 to hydroxyapatite is 2:3, and the obtained HA-SiO2 is treated at 800°C for 3h to obtain heat-treated HA-SiO2.

2. The method for preparing the carbon steel anti-corrosion composite coating according to claim 1, characterized in that: The added amount of the heat-treated HA-SiO2 is 3.0 g.

3. The method for preparing the carbon steel anti-corrosion composite coating according to claim 1, characterized in that: The mechanical grinding method in step 1 is: the low-carbon steel sample is polished with SiC sandpaper of different particle sizes until the surface is smooth, and the low-carbon steel sample is cleaned with deionized water each time the sandpaper is replaced.

4. The method for preparing the carbon steel anti-corrosion composite coating according to claim 3, characterized in that: The particle sizes are 100#, 400#, 500#, 800#, 1200# and 1500# respectively.

5. The method for preparing the carbon steel anti-corrosion composite coating according to claim 1, characterized in that: The degreasing method in step 2 is: ultrasonically treat the low carbon steel sample in acetone for 20 minutes, then ultrasonically treat the sample in a 40 g / L NaOH aqueous solution for 20 minutes, and then wash the sample with water.

6. The method for preparing the carbon steel anti-corrosion composite coating according to claim 1, characterized in that: The plating method in step 4 is: after rinsing the low-carbon steel sample with deionized water, immediately place it in a plating solution preheated to 85-90° C.; stir the plating solution and maintain the plating temperature at 85-90° C.

7. The method for preparing the carbon steel anti-corrosion composite coating according to claim 6, characterized in that: The plating time is 2 to 3 hours.

8. The method for preparing the carbon steel anti-corrosion composite coating according to claim 7, characterized in that: The plating time is 2h.

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